1. Field of the Invention
The present invention relates generally to a system for acquiring, examining and tracking a source, target or other object that radiates or reflects electromagnetic energy, and, more particularly, to such a system providing a an extended field of view without a corresponding increase in the number of sensor elements or detector elements and associated processing electronics.
2. Description of Related Art
In trackers or seekers, for example, both IR and normal visual spectral range, it has been conventional in the past in order to cover a relatively large viewing region to require that the optical system be mounted on a gimbal system so that it may sweep an extended field of regard. Typically, such a system has a relatively narrow effective field of view for its objective lens system (e.g., about 1.degree.) which must scan a substantially greater region of interest through the aid of the gimbal action. Moreover, other system sensing apparatus consists of a plurality of individual optical systems such that as an aggregate they view the total field of regard, of which each optical system has its own focal plane array and interconnection with processing equipment.
Exemplary of the size of the focal plane array driven by the number of light energy sensor elements needed, an optical system for a 1.degree. field of view requires a focal plane array in excess of 84,600 individual sensor elements with associated leads for each sensor element. If in an attempt to eliminate the gimbal, objective lenses with a field of view of, say, 60.degree. were used, a corresponding focal plane array of over 304.5.times.10.sup.6 sensor elements with individual leads would be required as well as substantial processing equipment enlargement. The addition to overall expense and complexity is apparent.
Also, the matter of weight and size of focal plane array with cryogenic cooling and signal and data processing equipment needed to produce an effective tracking system is especially critical in a missile or other airborne situation where both weight and space are at a premium.